Kale can grow in northern climates where more delicate members of the
cabbage family cannot. The "Kailyard" school of Scottish writers, which
included J.M.Barrie (author of "Peter Pan"), consisted of authors who wrote
about traditional rural Scottish life (kailyard = kale field), where, one
assumes, all the kale was organic. Kale is one of the most primitive
cabbages --- more sophisticated cabbage species have heads, and not just
leaves. Until the end of the Middle Ages, kale was the common green
vegetable in all of Europe
Because kale can grow well into winter, one variety is called Hungry Gap ---
named after that season in traditional agriculture when not even cabbage
could be grown. Kale actually tastes sweeter and tastier after being exposed
to a frost. Russian kale was introduced into Canada (and then into the U.S.)
by Russian traders in the 19th century.
Tender kale greens can provide an intense addition to salads, particularly
when combined with other such strongly-flavored ingredients such as
dry-roasted peanuts, tamari-roasted almonds, or red pepper flakes.
A traditional Portuguese soup, caldo verde, combines mashed potatoes, sliced
cooked spicy sausage, diced kale, olive oil, and broth. Kale freezes well.